Graduating from Boston Unversity, Ellis played in the big bands of Ray McKinley, Charlie Barnet and Maynard Ferguson, recorded with Charles Mingus and played with George Russell's sextet (at the same time as Eric Dolphy). It was in 1965 when he put together his first orchestra that he really started to make an impression in jazz. Ellis's big bands were distinguished by their unusual instrumentation (which in its early days had up to three bassists and three drummers including Ellis himself), and an openness towards using rock rhythms and electronics. Ellis invented the four-valve trumpet and utilized a ring modulator and all types of wild electronic devices by the late '60s. By 1971 his band consisted of an eight-piece brass section, a four-piece woodwind section, a string quartet and a two-drum rhythm section. A later unrecorded edition even added a vocal quartet. Ellis's last recording was at the 1977 Montreux Jazz Fesival, a year before his heart finally gave out.